The severe operating environment of earthmoving equipment and particularly crawler type tractors requires maximum quality in components if satisfactory service and life is to be realized. Specifically, the track chains which support, move and steer crawler type tractors and other earthmoving equipment encounter some of the highest loads and wear rates to which components of such equipment are exposed.
Such track chains must be made mechanically strong and heavy. However, they must also be flexible since they provide the means for moving the equipment in operation. Such basic incompatibility in function requires great care in fabrication, including careful attention to materials and close tolerances in dimensioning the parts in order to provide the necessary strength while preserving the equally necessary flexibility of the chain. Experience has proven that an articulated chain made of a plurality of link assemblies, each consisting of a pair of spaced interconnected links joined to each other and to another link assembly by concentrically disposed pin and bushing means will provide the necessary strength and flexibility. The links each include a pair of cylindrical bores, dimensioned to receive the pins and bushings respectively with a press fit of very close tolerance. Once assembled such chain is capable of providing long and dependable service in the operation of heavy earth moving equipment.
As is well known in the art, the assignee of this invention has for a number of years produced track chain known as sealed and lubricated track. This particular track includes seals between the bushings and the track links to maintain a quantity of lubricating fluid between the pin and the bushing to increase the life of the track chain assembly. This feature reduces the friction between these components thereby reducing fuel costs, making the machine more efficient, and reducing the amount of noise that is generally created by dry track chain joints.
However, assembly of such chain has presented a particular problem, the difficulty of aligning and pressing the parts of a link to assemble them with each other and with the pin and bushings. If the track press has become worn, which is the case of many presses being used in the field, the link bores are not properly aligned with the pin and bushing when they are being pressed thereon. When this happens the surface between the pin and the track link becomes scored and creates a leak path for the lubricant within the track chain. Loss of lubricant causes accelerated wear of the track joint resulting in the necessity of rebuilding the track chain.
It is a primary object of this invention to provide an apparatus for assembling track chain of the type described above, without causing the damage to the pin or link bore.
It is a further object of this invention to provide a self-aligning link locating and driving means for the track press to prevent the damaging of a misaligned pin and bushing to link bore.